


Yaku Morisuke and the Invisible Cat

by mozaikmage



Category: Haikyuu!!
Genre: Alternate Universe - Harry Potter Setting, Cats, Libraries, M/M, Magic, bc I am a hopeless nerd, it's hogwarts au time, mentions of L-space
Language: English
Status: Completed
Published: 2018-08-22
Updated: 2018-08-22
Packaged: 2019-07-01 05:50:24
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,621
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15767892
Author URL: https://archiveofourown.org/users/mozaikmage/pseuds/mozaikmage
Summary: Kuroo turns his cat invisible by accident. Yaku helps him find her.





	Yaku Morisuke and the Invisible Cat

**Author's Note:**

> the kuroyaku weekend prompt is universes so here is an alternate universe!  
> my very first fanfiction ever was a harry potter nextgen fic on the scholastic dot com forums when I was ten years old. nearly a decade later. here I am. writing hogwarts au fic for a cartoon about volleyball, because I am living my best life

The paper airplane zooms pointedly up the staircase and straight into the side of Yaku’s head as he’s walking to the Great Hall for dinner, the nose bending as it makes contact with his ear. Next to him, Suga snickers. “Wonder who that could be from, hm?” 

Yaku heaves a long-suffering sigh and mutters, “Why this,” as he unfolds the parchment. The familiar careful handwriting reads: “ _ Come to the library when you get this, it’s an emergency. P. S. Bring catnip if you have any. _ ” It’s signed with a scratchy yet cute drawing of a black cat that swishes its tail back and forth.

Yaku holds the parchment up so Suga can read it. “You got any catnip, Suga? Why does he need catnip? Is he trying to train Zelda to do tricks or something?”

Suga laughs outright. “You’re on your own for this one, sorry.” He pats Yaku’s shoulder a few times and says he’ll save him a spot at the Gryffindor table.

Yaku sighs, allows himself a moment to mourn the loss of his dinner, and heads up to the Hogwarts library.

Kuroo’s waiting for him at a table near the entrance. Well, under the table. He’s crawling around on his hands and knees and muttering, “Come here, Zelda, here, kitty kitty.” The librarian is scowling at him from her desk, waiting for him to break one of the library’s hundreds of rules and finally leave.

“What are you doing,” Yaku says flatly. 

“Yaku!” Kuroo immediately tries to jump up and hits his head on the underside of the table. “Fuck.” He lies down on his stomach instead, accepting his fate.

Yaku walks over and bends down to make eye contact with the idiot. It’s nice to have Kuroo lower in his field of vision than he usually is, Yaku thinks briefly, and then flicks him on the forehead. “What are you doing,” he says again.

“Good evening to you too,” Kuroo says, smiling up at him. Yaku’s reminded of why half the girls in their year are obsessed with Kuroo. That and the fact that they don’t know how much of a loser nerd Kuroo really is.   
He pulls the note out of the pocket of his robes and holds it up in front of Kuroo’s face. “I don’t have any catnip, in case you’re wondering. What happened?”

Kuroo scrambles up and dusts off his knees. His Ravenclaw tie is loose and crooked, his shirt rumpled. For once Kuroo’s attire matches his hair, Yaku thinks but doesn’t say. “It’s kind of a long story.” 

“I’m already missing dinner for this, so take your time,” Yaku says, unimpressed.

“You know how we learned Vanishing spells last year? When you Vanish something, you can’t get it back again later, because it goes into non-being and doesn’t just become invisible. So I started researching different kinds of invisibility spells and vanishing spells because it seemed interesting, and I decided to test one out on Zelda, and now she’s invisible  _ and I don’t know where she went!”  _ Kuroo takes a deep breath. “Which is why I need your help.” 

“Have you tried  _ revelio _ ?”

Kuroo nods. “Doesn’t work on cats, apparently. Neither does summoning. I could try summoning her collar, but that runs a risk of hurting her so I’d rather not. We gotta do this the Muggle way.”

Kuroo grins at him, golden eyes bright and shining with excitement. Yaku would never admit it, but he can’t say no to those eyes. “We’re gonna find my stupid invisible cat.”

They walk slowly through the stacks, listening for suspicious meows and looking for anything that may indicate Zelda’s presence while Kuroo rambles on in a whisper about the infinite size and depth of libraries and something he read in some Muggle fantasy book called ‘L-space’. 

“Kuroo,” Yaku says, “look at the situation you have created for yourself, and ask if you really want to believe that large libraries warp space and time into an alternate portal dimension or whatever.”

Kuroo cuts himself off abruptly. “You make a good point.”

He leads Yaku to the Invisibility section, where there’s a table piled in books and crumpled up bits of parchment, Kuroo’s school bag hanging off the back of a chair. There’s a puddle of ink in the corner of one of the parchment pieces, and a few tiny cat pawprints stepping out of it onto the table before disappearing. 

“She jumped off the table right after I cast the spell,” Kuroo explains. “And the carpet in this room is dark, so I can’t see her prints!”

Yaku squints at the carpeting for a minute, but is forced to concede this point.

“Why did you decide to turn your  _ pet cat  _ invisible instead of borrowing a Conjured animal from the Transfiguration professor?”

Kuroo is silent. “I...didn’t think of it,” he admits.

“You are the stupidest smart person I have ever met,” Yaku tells him. 

“You love it,” Kuroo replies, smirking.

The library is a dim place even in the middle of the day, but at dinnertime, after the sun has set, the glow of the chandeliers is barely bright enough to read by. And Kuroo’s cat is black with white feet, so finding her would be challenging even in full visibility.  “Any idea how long this spell is going to last?”

“Nope,” Kuroo sighs. “A few hours to a few days, I think. She’s going to use the shelves as scratching posts and once she’s visible again the librarian will skin her alive.”

“So check the shelves for scratch marks?” Yaku hesitates for a second before reaching up and patting Kuroo reassuringly on the back. “It’s going to be fine, okay? We’ll find her.”

“Yeah,” Kuroo replies. “Yeah, we will.”

The library closes in two hours, so they decide to go through every section in a counterclockwise circle pattern, starting with the Invisibility section and then working their way back around to it.

“Why didn’t you ask Kenma for help? Link and Zelda are siblings, aren’t they? You probably could’ve used Link to find Zelda.” Yaku remembers asking the muggle-born Kuroo about the cat names when they first became friends a few years back, and getting a lecture about the entire history of video games. Kenma’s still trying to work out a magical equivalent to the concept.

Kuroo laughs. “The cats don’t get along that well, and Kenma got detention for falling asleep in Potions again.”

They stand in front of the Restricted Section, Kuroo squinting at the dusty floorboards for pawprints. “I feel like there should be spells to keep cats out of here, right?”

But Yaku’s still confused as to why Kuroo had called him to help with this out of all people and not anyone else from his sizeable circle of friends.

“What about Bokuto? Your partner-in-crime?”

“Bokuto wouldn’t skip a meal for something like this,” Kuroo murmurs, distracted.

“And you just assumed I would?”   
“You’re here, aren’t you?” Kuroo turns around and flashes a grateful smile at Yaku, which is embarrassing. Yaku looks around wildly for a distraction. And then he sees it.

He grabs Kuroo’s wrist and drags him across the library. “I have an idea.”

The Care and Keeping of Magical Creatures section is in an alcove near the librarian’s desk, and there’s a big metal cage holding an assortment of books with wings, fangs, and other animalistic properties. The librarian occasionally throws bits of scrap paper in there to feed them, but mostly the books are in the cage for the safety of the humans in the library.

“Zelda’s a hunter, right?”

Kuroo cackles. “A  _ warrior cat,  _ you could say. Sorry, muggle kid’s book joke. But yeah, she brings me dead sparrows and mice sometimes.”

“You’re such a nerd. Anyway.” Yaku gestures at the cage. “If she likes hunting animals, wouldn’t the cage of animal-like books interest her?”

Kuroo gasps, and then smacks his forehead. “Wow, I should’ve thought of that.” 

He crouches down in front of the cage and tentatively sticks his hand out. He gasps. Zelda must’ve smelled him and come over to get petted. 

Kuroo wastes no time in undoing the invisibility spell, and soon enough Zelda is sitting snugly in his arms, slightly dusty from her library adventure and disgruntled at her playtime being interrupted.

“It worked, it worked, it worked!” Kuroo exclaims, spinning the cat around in blatant disregard of the librarian’s warning glare. He puts her down, whispering “do not fucking go anywhere else or I will lock you in my dorm room until the end of the term.”

Before Yaku can react, Kuroo grabs him in a hug too. “Thank you so much for your help, you’re a hero to wizardkind, no, a hero to  _ humanity _ \--”

Kuroo’s face is close and he’s still talking about something unnecessary, so Yaku just tilts his up head slightly and closes the gap. Kuroo stiffens in surprise for a moment, and then kisses back with unexpected force.

The librarian tsks loudly from her desk, and Kuroo laughs. Yaku kisses him again, because he can.

“Kenma doesn’t actually have detention today, I just wanted an excuse to spend time with you alone for once,” he tells Yaku, once they leave the library and sneak down to the kitchens to make up for missing dinner. Zelda is sitting on Kuroo’s shoulder, like a parrot on a pirate captain.

“Did you lose your cat on purpose?”

“Of course not.” Kuroo looks almost offended at the question. “I just...took advantage of the opportunity. Created by the cat being lost.”

Yaku laughs a little, breathlessly. “I can’t believe I like you.”

“Neither can I, to be honest.” Kuroo says, looking absolutely delighted. “No take-backs.”

“No take-backs,” Yaku agrees.

  
  


**Author's Note:**

> talk to me on [tumblr](http://cubistemoji.tumblr.com/) or [twitter](http://twitter.com/mashazart/)  
> 


End file.
